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EPE Journal Volume 19-2 - Papers
- Silicon Based Trench Hole Power Capacitor
- Design of a Driver for Thyristors Using a New Extra Flat Planar Transformer Without Magnetic Circuit
- High-Performance Thermal Management for High-Power High-Frequency Transformers
- Minor-Loop Gain as a Source of Information on Robust Stability and Transient Performance in an Interconnected System
- A Novel Nine-Switch PWM Rectifier-Inverter Topology For Three-Phase UPS Applications
- High-Voltage Closed-Loop Power Supply for Ozone Generators
- A Model for Techno-Economic Optimization of Wind Power Combined with Hydrogen Production in Weak Grids
EPE Journal Volume 19-2 - Editorial
By J. Peracaula; E. Dede
EPE 2009, the European Power Electronics and Applications Conference in Barcelona, sponsored by the EPE Association and the National Organizing Committee, goes strongly renewable and industrial. Do not miss an outstanding opportunity! Make sure you are there: www.epe2009.com!
EPE Journal Volume 19-2 - Papers
By S. E. Berberich; J. vom Dorp; A. J. Bauer; H. Ryssel
In this work, we introduce a high voltage 3D-capacitor as a novel passive power device for a 400V application. This device is realized in silicon technology which allows high process reproducibility, high accuracy in capacitance values, and high quality of the dielectric layers (i.e., endurance at high electric field strengths). It can be manufactured discrete or as part of a monolithic integrated circuit. The outstanding properties of the device are a high ratio of capacitance value to consumed silicon area (capacitance enlargement of more than a factor of 16 in comparison to plane capacitors) and very stable capacitance values over a broad temperature range (i.e., average of 24ppm/°C from 20-175°C).
By Férid Kourda
The control of power thyristors requires in most applications, insulation between the control reference and the gate cathode of the controlled thyristors. For this purpose, impulses transformers are used with magnetic circuits whose operation in high frequency allows reducing their weights and volume. In this paper, we propose to eliminate the magnetic circuit and to use the PCB (Printed Circuit Board) as a support of the primary and secondary impressions of the transformer operating at a frequency ranging between 1 and 2 MHz for the thyristors control. This approach allows the volume and weight reduction by a factor more than 20. An experimental procedure was used for the evaluation of the internal transformer parameters. The designed insulating thyristor driver was tested and validated for an induction heating application.
Note that, this work can be present a good energy transfer capability for very low power applications (a few watts), like insulated power supply, insulated data transmission, insulated data transmission in contactless electrical energy transfer, insulated sensors, the communications between parts moving distant of the order of the mm….
By M. Pavlovsky, S.W.H. de Haan, J.A. Ferreira
The paper discusses a new approach to the design of thermal management for high-frequency high-power transformers. Proposed thermal management concept is based on heat removal by conduction aided by advanced heat conducting elements (heat pipes). The heat is collected on dedicated surfaces called thermal surfaces where the heat exchange with the environment occurs. Several implementations of heat removal paths are proposed and core and winding structures are analysed in order to reach an optimal heat removal solution. Further, the proposed heat removal concept is evaluated with a focus on the design and evaluation process of the thermal management system. The paper is concluded with experimental results on a 50 kW transformer prototype that utilises the proposed heat removal concepts. Experimental results of a full power converter prototype are briefly discussed as well.
By Matti Karppanen; Teuvo Suntio
Dynamic analysis of the interconnected regulated systems is commonly based on the minor-loop gain which composes of the ratio between the output and input impedances defined at an arbitrary interface within the system. The stability of the system is guaranteed, when the minor-loop gain satisfies Nyquist stability criterion. Usually, the stability conditions are expressed as a certain forbidden region in a complex plane out of which the minor-loop gain should stay for stability to exist. The robustness of the stability is guaranteed requiring certain phase and gain margins to exist. It is also natural to assume that the existence of robust stability means also the existence of acceptable transient behavior. The paper investigates the validity of those expectations. According to the investigations, the system-level minor-loop gain measured at an arbitrary interface does not necessarily contain any other information than the existence of stability. The theoretical analyses are based on a set of transfer functions describing the dynamics of a switched-mode converter. Practical evidence is provided based on a small-scale industrial prototype system composing of voltage-mode-controlled buck converters.
By C. Liu; B. Wu; N. Zargari; D. Xu; J. Wang
A novel three-phase PWM rectifier-inverter topology (Fig. 2) for UPS applications is proposed in this paper. The topology uses only nine IGBT devices for AC/AC conversion through a quasi d.c. link circuit. This converter topology features sinusoidal inputs and outputs, unity input power factor, and more importantly, low manufacturing cost. The operating principle of the converter is elaborated and a dedicated space vector modulation scheme is presented. The performance of the proposed converter is verified by experiments on a 5 kVA prototyping UPS system.
By J. Marcos Alonso; Carlos Ordiz
In this paper the design, implementation and experimental results of a high-voltage power supply for ozone generation are presented. The power stage arrangement is formed by a buck converter plus a current-fed parallel-resonant push-pull inverter. The buck converter is used to both regulate the output power against the line voltage variation, and to control the power delivered to the ozone generator (OG). The push-pull inverter assures safe operation of the OG by working at the parallel resonant frequency given by the high-voltage transformer plus OG characteristic. The closed-loop operation of the proposed converter is analyzed and implemented as a method to compensate variations in the line voltage and in the OG. A low cost commercial UC3872 integrated circuit is used to control both the push-pull inverter and the buck converter, providing OG power control and regulation via buck converter duty cycle. Protections against short circuit and no load operation are also implemented. Experimental results for a 100 W prototype are shown and discussed.
By Christopher J. Greiner; Magnus Korpaas; Terje Gjengedal
This paper presents a two-step method for dimensioning and time-sequential operation of Wind-hydrogen (H2) plants operating in power markets. Step 1 involves identification of grid constraints and marginal power losses through load flow simulations. Step 2 involves solving a model for optimization of the component sizes (wind turbine, electrolyser, H2 storage, fuel cell) and the corresponding time-sequential operation of each component. Results are presented through a case study of a Norwegian island with good wind resources, a weak connection to the main transmission grid and a commuting ferry, constituting the H2 load. Main results show that if H2 consumers are willing to pay at least 0.31-0.34 ? per Nm3, the wind power penetration could be cost-effectively increased by 1.8-1.9 MW by including an average H2 load of 1.36 MW. The H2 plant is very dependent on power import and H2 storage capacity is only 1.5 - 2 days of average demand. The operational flexibility of the H2 plant opens for a more optimal power exchange with the grid. It is concluded that H2 produced from wind power could be competitive with fossil fuels. H2 is however not cost-effective as electric energy storage for wind power plants operating in power markets.